Process for the manufacture of oxygenated organic compounds



Patented July 28, 1931 ERNST PANSEGRA'U, O1! KREEELD, GERMANY,

assrcnon 'ro I. e. rannrmmnusmn AKTIEHGBELQCEAFT, OF FBANKIOBT-ON-THE-MAIN, GERMANY, A. CORPORATION PROCESS FOR THE MANUFACTURE OF OXYGENATED ORGANIC COMPOUNDS No Drawing.

The present invention relates to the oxidation of l substituted benzenes and thelr halogenate derivatives by means of molecular oxygen or gases containing oxygen. It particularly relates to a process In wh1ch the oxidation is carried out under su eratmospheric pressure in the presenceo a l1qu1d aqueous phase and of an oxidation catalyst.

I have found that alkyl substituted benzenes and their halogenated derivatives, for example, toluene, xylene, ethyl benzene, chloro toluene and the like, are readily 0x1- dized by reacting upon them with molecular oxygen or gases containing oxygen under conditions of elevated temperature and superatmospheric pressure in the presence of a substantial proportion of water and of a small quantity of an oxidation catalyst. In carry-.

ing out the oxidation in this manner the presence of an alkaline or other acid-bindmg agent may be dispensed with. Under the aforesaid conditions oxidation generally proceeds moderately of oxidation, which otherwise are 'easily attacked by further oxygen, ma be isolated. By varyingthe temperature an the duratlon of the oxidation and by graduating the amount of water added to the reaction mixture, the eflect. of oxidation, i. e. the species of o gena-ted compounds resulting, 1s mfluence d of water, in particular, has the effect of moderating the oxidation. In general I use at least three parts by weight of water for each part of t e substance to be oxidized.

Another -means of moderating the action of oxygen consists in adding a considerable amount. of carbon dioxide to the gas containin o The ox id fi t m catalysts empioyed which are essential to the process may of different kinds. Oxidic compounds of heavy metals (i. e. metals havin a specific gravity of 5 and over) especial y oxides and hydrated oxides thereof have given excellent results. The state of division of the oxidation catalyst is however, of great importance, since a more finely divided oxidation catalyst offering a larger surface exerts a greater action. Among the catalysts which have been found 'ing to the formula and the primary products to a large extent. An increasing ratio,

Application filed June 18, 1929, Serial No. 371,959, and in Germany .Tune 19, 1928.

suitable in carrylng out the invention, the following may be named: copper oxide, copper hydroxide, nickel oxide, nickel hydroxide, cobalt oxide, cobalt hydroxide, iron oxlde, iron hydroxide, manganese oxide, cerium oxide, osmium oxide, vanadium oxide. The iron oxides, especially the hydrated oxides, such as the semi hydrate correspond- Fe0.0H, are particular- 1y appropriate in most cases. These oxidatlon catalysts may be used singl or mixed with one another; for example erric oxide mixed with a small quantity of another oxidation catalyst, such as mixtures of hydrated ferric oxide With chromium oxide, uranium ox1de,.copper oxide, cerium oxide, zinc oxide or the like, are especially suitable.

One preferred method of carrying out my 7 process cons1sts in introducing the substance to be oxidized, Water and the oxidation catalyst into an acidand pressure-proof vessel provided with a stirring device, heating the mixture to the reaction temperature and then forclng gaseous oxygen or a gas containing oxygemfor example, air, into the vessel until the desired amount of oxygen has been absorbed. If desired or necessary, the escaping gases are cooled down under superatmospheric pressure and thereupon he reaction temperature compound to be oxidized; itlies in all cases above 150 C. and is regulated in such a manner that the vapor tension of the organic compound is high enough to form a mixture of vapor and oxygen in the vapor space the composition of which lies beyond the limits known for explosive hydrocarbon vaporoxygen mixtures, i. e. that the vapor-oxygen mixture contains considerably more vapor than any ignitable or explosive mixture.

allowed to expand. depends upon the oreover the presence of water in the rean-v tion mixture diminishes the possibility of 'forming explosive gas mixtures.

y invention is illustrated b the following examples, but is not'restrlcted thereto. The parts are by weight.

Example 1 down, sodium carbonate is added; steam is introduced and from the distillate the unand dibenzyl ether.

changed toluene is removed by means of fractional distillation. The residue yields benzaldehyde, besides traces of benzyl alcohol Some benzoic acid 1s furthermore obtained by acidulating the sodium carbonate solution remalning after the distillation by steam.

Example 2 400 parts of toluene, 1500 parts of water and a mixture of/l parts of hydrated ferric oxide Fe0.0H and 1 part of uranium oxide are treated with about 225 and under a total pressure of about 60 atmospheres for four hours, as,

shown in Example 1. After adding sodium carbonate sufiicient to neutralize all the acid present, the reaction mixture is worked. up by distillation by means of steam; The portion' distilling with steam contains in addition. to unchanged toluene some benzaldehyde (besides traces of benzyl alcohol and dibenzyl ether) the res1due yields 200 parts of benzoic acid.

Ewa/mple 3 250 parts of toluene, 1500 parts of water and 5 parts of ferric oxide (obtained from a ferrous chloride solution by precipitating ferrous hydroxide, oxidizing it and calcining the precipitate at about 700 C.) are treated with air at a temperature of about 230 C. and

under a total pressure of about atmos-' pheres (analogous to Example 1). Working up in accordance with Examples 1 and 2 yields unchanged toluene, benzaldehyde and benzoic acid.

E mample 4 5 atmospheres of carbon dioxide are forced into an autoclave containing a mixture of 400 parts of toluene, 1500 parts of Water and 4 parts of hydrated ferric oxide Fe0.0H at normal temperatures. Then the autoclave is heated to 220 C. and oxygen forced into the heated mixture until a total pressure of 60 atmospheres is attained. The residual gas is discharged through a throttling valve at such a rate that the escaping gas contains about '30 percent of carbon dioxide. v

After 3 hours the content of the autoclave is allowed to cool down and worked up as shown in the foregoing examples. In addition to unchanged toluene and some benzaldehyde there is obtained as a main product benzoic acid of particular purity.

oxygen at a temperature of a Example 5 ing up (analogous to Examplel) yields in' addition to unchanged p-xylene 60' parts of p-tgluic aldehyde and 120 parts of .p-toluic acl Ewample 6 500 parts of m-xylene, 500 parts of water and 5 parts of vanadium pentoxide are heated to a temperature of about 220 C. whilst forcing oxygen into the reaction mixture for 5 hours, the total pressure being 30 to 40 atm ospheres. Equal amounts of m-toluic a1- dehyde and m -toluic acid are obtained (besides traces of isophthalic acid).

Example '7 500 parts of ethyl benzene, 500 parts of- -water and 5 parts of hydrated ferric oxide are treated with oxygen at a temperature of 170 C. and under a total pressure of about 20 atmospheres for 2 hours." 'Working up yields 110 parts of a mixture consisting of about 30 percent of phenyl methyl carbinol and 70 percent of acetophenone, besides some benzoic acid.

Example 10 200 parts of p-chloro toluene, 1500 parts of water and 2 parts of hydrated ferric oxide Fe0.0H are treated with oxygen at a temperature of about 230 C. and under a total pressure of about 50 atmospheres for 3 hours. Working up as in the foregoing examples yields 20 parts of p-chloro benzaldchyde and 80 parts of p-chloro benzoic acid.

I claim:

1. A process which comprises reacting upon an alkyl substituted benzene which may be further substituted by halogen with a gas I containing oxygen under conditions of elevated temperature above 150 C. and superatmospheric pressure in the presence of a liquid aqueous phase and an oxidation catalyst comprisingan oxidic compound of a heavy metal.

2. A process which comprises reacting upon an alkyl substituted benzene which may be further substituted by halogen with a gas containing oxygen at temperatures between 17 0 C. and 240 C. and pressures between 20 and 7 0 atmospheres in the presence of a liquid aqueous phase and an inorganic oxidation catalyst comprising an oxidic compound of iron.

3. A process which comprises reacting-upon an alkyl substituted benzene which may be further substituted by halogen with agas containing oxygen at temperatures between 170 C. and 240 C. and pressures between 20 a temperature of v upon an aromatichydrocarbon with a containing oxygen under conditions of eleand atmospheres inthe presence of a liquid aqueous phase and an inorganic oxidation catalyst comprising a hydrated ferric oxide.

1. A process which comprises reacting upon alkyl substituted benzene which may be further substituted by halogen with a gas containing oxygen at temperatures between 170 C. and 210 C. and pressures between 20 and 70 atmospheres in the presence of a liquid aqueous phase and an inorganic oxidation catalyst comprising 'a semihydrate of ferric oxide.

5. A process which comprises reacting upon toluene with a gas containing oxygen under conditions of elevated temperature above C. and superatmospheric pressure in the presence of a liquid aqueous phase and an inorganic oxidation catalyst comprising a hydrated ferric oxide.

6. A process which comprises reacting u on toluene with oxygen at a temperature of alEout 225 C. and under a pressure of about 60 atmospheres in the presence of at least three parts water for each part of toluene and of semihydrate of ferric oxide having the composi tion Fe0.0H.

7. A process which comprises reacting gas vated temperature above 150 C. and superatmospheric pressure in the presence of a liquid aqueous phase, carbon dioxide andan oxidation catalyst comprising an oxidic compound of a heavy metal. 1

8. A process which comprises reacting upon an alkyl substituted benzene which may be further substituted by halogen with a gas containing oxygen under conditions of elevated temperature above 150 C. and superatmospheric pressure in the presence of a liquid aqueous phase and an oxidation catalyst comprising an oxidic compound of iron.

9. A process which comprises reacting upon an alkyl substituted benzene which may be further substituted by halogen with a gas containing oxygen at temperatures between C. and 240 C. and pressures between 20 and 70 atmospheres in the presence of a liquid aqueous phase and an inorganic oxidation catalyst comprising an oxidic compound of a heavy metal.

In testimony whereof I havehereunto set m hand. y ERNST PANSEGRAU. 

